1. Field of the Invention
The present invention relates to a liquid crystal display device (LCD) for displaying images utilizing electrooptic anisotropy of liquid crystal, and more particularly to a configuration of an electrode thereof.
2. Description of the Related Art
LCDs are compact, thin, and low power consumption devices, and have therefore been developed for practical use in the field of office automation (OA) equipment, audio-visual (AV) equipment, and others. In particular, an active matrix LCD having a thin film transistor (hereinafter referred to as a TFT) as a switching element is theoretically capable of static actuation with a 100% duty cycle in a multiplexed manner, and is therefore applied to a large screen for displaying motion pictures with a high resolution.
A liquid crystal layer is sandwiched between a common electrode shared by a plurality of pixels and a display electrode driven by a TFT. A region where one display electrode is formed corresponds to each pixel area, and a slit is formed in the common electrode corresponding to each pixel. Such a slit is called an orientation control window for maintaining a constant direction of inclination of liquid crystal molecules. The orientation control window may be composed of, for example, a linear slit and a V-shaped slit coupled to and branched from each end of the linear slit.
The shape of the orientation control window de scribed above, and arrangement thereof with respect to the display electrode, must be determined taking into consideration the aperture ratio, response speed, and the like.
An object of the present invention is to achieve appropriate arrangement of the orientation control window and the display electrode.
In order to accomplish the above object, a liquid crystal display device according to the present invention has a distance or spacing in the range between 25 xcexcm and 30 xcexcm at the most between an orientation control window and a display electrode on a display plane. Although the response speed tends to increase with a decrease in the above distance when the distance is 30 xcexcm or longer, it has been proved that the response speed shows substantially no change when the distance is 30 xcexcm or shorter, especially shorter than 25 xcexcm. On the other hand, a smaller distance results in a reduction in displayable area per pixel, which is likely to cause decreases in aperture ratio and contrast. Consequently, the above distance is preferably 30 xcexcm or smaller, and is more preferably in the neighborhood of 30 xcexcM. The orientation control window is preferably about 7 xcexcm.
Thus, the present invention provides a liquid crystal display device with increased area where the orientation of liquid crystal molecules can be controlled, i.e. with increased contrast of pixels and enhanced response speed.